custom-save-variables: Unknown requested feature: nil

custom-save-variables: Unknown requested feature: nil

[David Reitter]

I've started getting an "Unknown requested feature: nil" message when  
doing "Save Options" (via custom-save-all, custom-save-variables).

I don't know what caused it. The below change makes the message go  
away, but it's quite possibly not the right fix.


*** simple.el	26 Nov 2005 16:33:45 +0000	1.770
--- simple.el	30 Nov 2005 20:06:14 +0000	
***************
*** 3260,3266 ****
   Invoke \\[apropos-documentation] and type \"transient\" or
   \"mark.*active\" at the prompt, to see the documentation of
   commands which are sensitive to the Transient Mark mode."
!   :global t :group 'editing-basics :require nil)

   (defvar widen-automatically t
     "Non-nil means it is ok for commands to call `widen' when they  
want to.
--- 3260,3266 ----
   Invoke \\[apropos-documentation] and type \"transient\" or
   \"mark.*active\" at the prompt, to see the documentation of
   commands which are sensitive to the Transient Mark mode."
!   :global t :group 'editing-basics)

   (defvar widen-automatically t
     "Non-nil means it is ok for commands to call `widen' when they  
want to.

Re: custom-save-variables: Unknown requested feature: nil

[Luc Teirlinck]

David Reitter wrote:

   I've started getting an "Unknown requested feature: nil" message when  
   doing "Save Options" (via custom-save-all, custom-save-variables).

   I don't know what caused it. The below change makes the message go  
   away, but it's quite possibly not the right fix.

That `:require nil' came from the following change by Stefan Monnier
on 2002-09-13:

     * simple.el: Provide `simple'.
     (transient-mark-mode, line-number-mode, column-number-mode):
     Pass an explicit `:require nil' argument.

I do not know the reason for that change.  Apart from the listed
variables, size-indication-mode also has the `:require nil' (also in
simple.el).

Sincerely,

Luc.

Re: custom-save-variables: Unknown requested feature: nil

[Luc Teirlinck]

David Reitter wrote:

   I don't know what caused it. The below change makes the message go  
   away, but it's quite possibly not the right fix.

I believe that it is the right fix, but the same fix needs to be
applied to three other options, as I pointed out in my earlier reply.

   That `:require nil' came from the following change by Stefan Monnier
   on 2002-09-13:

	* simple.el: Provide `simple'.
	(transient-mark-mode, line-number-mode, column-number-mode):
	Pass an explicit `:require nil' argument.

   I do not know the reason for that change.

Whatever the reason for that change, it seems wrong.  I believe that
it tried to undo an at the time automatic :require written by
define-minor-mode.  It did not do that.  Instead it tried to require
the library nil.el _in addition_ to the other require, instead of
overwriting it.  (A defcustom can have more than one :require.  These
do not override each other.  Instead, all libraries are required by
the defcustom.)  This did not lead to an error, because of code in
custom-save-variables:

	    (when (and (symbolp request) (not (featurep request)))
	          (message "Unknown requested feature: %s" request)
		  (setq requests (delq request requests))))

which eliminated the `:require nil'.

If you disable the above piece of code and customize transient-mark-mode
and save it, then the next time you try to load your init file, it
will yield an error because it can not open the library nil.

Not only did the 2002 change not do what it tried to do, it is also no
longer necessary to try to do it, since the following more recent change:

2005-06-26  Stefan Monnier  <monnier@iro.umontreal.ca>

	    * emacs-lisp/easy-mmode.el (define-minor-mode): Don't
	    automatically add a :require to the defcustom.

I believe that the `:require nil' should be deleted in the defcustoms
for transient-mark-mode, line-number-mode, column-number-mode and
size-indication-mode.

Sincerely,

Luc.

Re: custom-save-variables: Unknown requested feature: nil

[Luc Teirlinck]

>From my earlier message:

      That `:require nil' came from the following change by Stefan Monnier
      on 2002-09-13:

	   * simple.el: Provide `simple'.
	   (transient-mark-mode, line-number-mode, column-number-mode):
	   Pass an explicit `:require nil' argument.

      I do not know the reason for that change.

In my earlier message, I inadvertently made this look like a quote
from David Reitter.  Instead I was quoting from a still earlier
message of mine.

Sincerely,

Luc.

Re: custom-save-variables: Unknown requested feature: nil

[Richard M. Stallman]

    I believe that the `:require nil' should be deleted in the defcustoms
    for transient-mark-mode, line-number-mode, column-number-mode and
    size-indication-mode.

Thanks.  Would you please do it?

Re: custom-save-variables: Unknown requested feature: nil

[Luc Teirlinck]

Richard Stallman wrote:

       I believe that the `:require nil' should be deleted in the defcustoms
       for transient-mark-mode, line-number-mode, column-number-mode and
       size-indication-mode.

   Thanks.  Would you please do it?

Done,

Sincerely,

Luc.